Metod för predistortion av icke-linjära anordningar

摘要

New technology is described to calculate and optimize a pre-distorter avoiding the need of time-alignment between input and output of the amplifier. An analog output spectrum is used to compute an optimum pre-distorter, either in digital or analog format. The output spectrum is used to optimize intermodulation performance rather than trying to match the input spectrum to the output spectrum. The output spectrum (except for a possible gain constant) can be used as input to the optimization procedure. Since the intermodulation products usually are of much lower amplitude than the carriers themselves, it can be taken as the input spectrum without major loss of confinement. Mathematical procedures to calculate a pre-distorter using only the output signal are outlined.